Dishwashing apparatus



May 20, 1952 J. J. MCDONALD ET AL DISHWASHING APPARATUS Filed F'eb. 19,.1947 2 SHEETS-SHEET l May 20, 1952 J. J. MCDONALD ET Al.

DISHWASHING APPARATUS 2 SHEETS-SHEET 2 Filled Feb. 19, 1947 Patented May20, T952 DISHWASHING APPARATUS John J. McDonald, Newton, and Stephen D.Klyce, Lexington, Mass., assignors to The McDonald Company, Boston,Mass., a corporation of Massachusetts Application February 19, 1947,Serial No. 729,468

7 Claims.

This invention relates to improvements in dishwashing apparatus and moreparticularly to such apparatus in which oppositely directed wash spraysimpinge from opposite sides upon dishes held in a rack or the like whichmay be removably supported between the spray pipes or nozzles. Suchapparatus customarily has additional rinse sprays for directing rinsewater over the dishes subsequent to a predetermined period of operationof the wash sprays.

Heretoiore, dish-washing apparatus of the general type to which theinvention relates have had oppositely disposed spray pipes or nozzlesfor directing wash sprays simultaneously from above and from belowagainst dishes held in a rack between the upper and lower spray pipes.In the prior apparatus, the opposed sprays, supplied from a commonpressure supply conduit, cannot eiectually utilize the total availablepressure because that total pressure must be divided between the upperand the lower sprays. Also, with the upper and lower wash spraysopposing each other, there is a tendency for the sprays to neutralizeeach other at the region where the dishes are located and such pressureor force as the individual sprays initially may have had for dislodgingfood particles from the dishes may be diminished considerably before thewash water comes into washing and food-dislodging contact with thedishes.

It is among the objects of our present invention to provide adish-washing apparatus wherein upper and lower wash sprays havealternating operation so that the total available pressure of the washwater is utilized alternately for the upper and the lower sprays, and sothat the full pressure of the individual sprays is effective forcleaning dishes without diminution by opposing sprays. We have foundthat a definitely greater efficiency of cleansing action is attained bydirecting forceful washing sprays alternately in one direction and thenin the opposite direction, as compared with prior dish-washingprocedures. If food particles are only partially dislodged by theoperation of 'the sprays in one direction, a subsequent agitationthereof by the oppositely directed sprays completes the dislodgment,whereas in prior apparatus such particles frequently are lodged atneutralized spray regions and fail of being dislodged.

Another object is to provide a'dish-washing apparatus wherein there areupper and lower oppositely directed wash water spray pipes of which onlythe upper sprays, for example, operate for a predetermined period oftime in response to manual' actuation of a starting mechanism, and thenthe upper sprays automatically stop and only the lower sprays operatefor a predetermined period of time, followed again automatically byoperation only of the upper sprays, and so on for a predetermined numberof alternations of the sprays and ultimate stopping of both the upperand the lower wash sprays.

A further object is to provide a dish-Washing apparatus having upper andlower oppositely directed wash water sprays alternating automaticallythrough a predetermined wash cycle and then adapted automaticallyl tostop, and having upper and lower oppositely directed rinse water sprayswhich may be manually or automatically operable from above and below thedishes following stopping of the wash sprays.

A still further object is to provide a dish-washing apparatus havingspray means for directing hot water on dishes held in a spray chamberand including means for inducing outflow from the chamber ofmoisture-laden air and inflow of relatively dry and cool air which israpidly circulated in drying relation to the dishes subsequent to a washcycle of the apparatus and prior to opening of the spray chamber forremoval of the dishes.

Another object is to provide a dish-washing apparatus wherein upper andlower ywash sprays operate alternately and wherein rinse sprays operateautomatically at the end of the wash cycle and are separately operableindependently of a wash cycle.

Yet another object is to provide a dish-washing apparatus wherein thewash water is more effectively rid of food particles prior to itsre-circulation through the wash water spray pipes, as cornpared withprior comparable dish-washing apparatus.

It is, moreover, our purpose and object generally to improve thestructure and eiiiciency of dish-washing apparatus and more especiallysuch apparatus having upper and lower oppositely di- IeCted Wash WaterSprays.

Fig. 5 is a diagrammatic view of the piping and electrical connections;and

Fig. 6 is a fragmentary cross-sectional detail showing the passage forair inflow past the lower portion of the closure when the latter isclosed.

Referring to the drawings, upper and lower horizontally disposed washwater spray pipes are indicated at I0 and I2 respectively. The upperspray pipes I0 are supported by and connected to the horizontal manifoldpipe I4 while the lower spray pipes I2 are similarly supported by andconnected to the horizontal manifold pipe i6. Both of the horizontalmanifold pipes I4, I6 are connected to the vertical supply pipe I6 whoselower end is connected to the pump 28 which may be belt driven as at 22from the electric motor 24.

The spray pipes I0, I2 and their supply pipes I4, I6 and I8 are allenclosed within a generally rectangular housing indicated generally at26 which defines a chamber 2l within which dishes to be washed may besuitably arranged and supported. One wall of the chamber 2l convenientlymay be provided with a transparent panel 28 opposite the region wherethe washing takes place, which is between the upper and lower spraypipes I0, l2, so that action interiorly of the housing may be observed.Also, an access Opening 30 in the side wall of housing 26 may be closedby any suitable openable closure which, as Shown, is a verticallyslidable panel 32. If desired, a similar slidable vpanel 34 may lbeprovided in the opposite side wall of the housing. The dishes preferablyare arranged in a suitable rack (not shown) which may be inserted inchamber 2'I through the access opening 30.

As best seen in Fig. l, the housing 26 has the inclined bottom wall 35extending a substantial distance laterally and slightly downwardly fromone side wall to the other. Short of the vertical plane of the righthand side wall of the main housing 26, this bottom wall 35 joins thevertical wall 36 which constitutes a side wall of a return chamber 38which projects substantially beyond the vertical plane of the right handside wall ofthe main housing 26 and which is open into the interior ofthe main housing at 40.

Return chamber 38 is suitably mounted on a base 42 and constitutes alsupport for the main housing 26 above. bottom wall 35 and base 42 forsupporting the left hand side portion of the main housing in verticallyspaced relation to base 42, as seen in Fig. 1. Legs 44' support the base42.

The pump 20 conveniently is located in the space between Ibottom wall 35and base 42, to one side of Vertical wall 36. It is shown primarilysupported at 46 on base 42, with its inlet 48 connected to the returnchamber 38 and its outlet 50 connected to the lower end of the verticalsupply pipe I8. The electric motor 24, for driving the pump, also may besupported on base 42, in

Legs 44 extend between the the space between the base 42 and bottom wall35 of main housing 26.

According to the invention, a wash water flow control valve indicatedgenerally at 52, is located at the juncture of the lower horizontal washmanifold pipe I6 with the vertical supply pipe I8. As represented in theshowing of Figs. 3 and 4, valve 52 is rotatable to connect verticalsupply pipe I8 to the upper wash manifold pipe I4, in which position itcuts oi flow from vertical pipe I8 to the lower wash manifold pipe I6,and to connect the supply end of vertical supply pipe I8 to the lowerwash manifold pipe I6, in which p0- sition it cuts off flow in verticalpipe I8, beyond the valve, to the upper wash manifold pipe I4.

Alternating rotation of valve 52, first in one direction and then in theopposite direction, is accomplished by the reciprocations of a piston 54in a cylinder 56 which is reciprocated by fluid under pressure deliveredinto cylinder 56 first on one side of the piston and then on the otherside. As herein shown, the cylinder 56 is connected to the building hotwater supply system, the pipe 58 Ibeing arleader from such a system andextending vertically within main housing 26 with itsA open lower endpreferably disposed below the access opening 30, for supplying hot washwater to thelower portions of the housing, especially to the returnchamber 38, it being understood that soap or the like is added to thewash water as may be desired. A manual valve 60 in pipe 58 will beclosed excepting when the housing is being supplied with wash water.

A pipe 62 leads from pipe 58 on the supply side of manual valve 60 andhas a four-way valve 64 therein for passing water under pressure throughconduit 66 to cylinder 56 on the upper side of piston 54 while thecylinder at the lower side of the piston is connected through conduit68, valve 64 and conduit 10 to vertical pipe '58 on the apparatus sideof manual valve 60, or for passing water under pressure through pipe 68to cylinder 56 on the lower side of piston 54 while the cylinder at theupper side of the piston is connected through pipe 66, valve 64 and pipe'I0 to vertical pipe 58, as before. Hence, when pressure liquid isacting at one side of piston 54 to drive it in one direction in cylinder56, the cylinder at the other side of the piston is connected forexhaust of liquid into the housing of the apparatus.

Piston 44 has a piston rod 'I2 depending through the lower end ofcylinder 56, with link connection at 14 toan arm 16 which is rigid withthe rotatable element of wash water supply control valve 52. When thepiston is driven in one direction, valve 52 is operated to connect onlythe upper wash spray pipes I0 for discharge, and when the piston isdriven in the opposite direction, valve 52 is operated to connect onlythe lower wash spray pipes I2 for discharge.

It is a feature of the invention that the upper and the lower wash watersprays operate alternately. For example, the upper and lower wash spraysmay operate alternately with the upper sprays on for six seconds, andthen olf for six seconds and with the lower sprays off for six secondswhile the upper sprays are on, and on for six seconds while the uppersprays are olf. A washing cycle may extend through sixty seconds, forexample, with the upper sprays on live times for six second operationsduring the cycle and with the lower sprays similarly on flve times forsix second operations during the cycle, although the time period ofoperation and the number of operations per cycle may be varied asdesired.

As hereinbefore described, the reciprocations of piston 54 operate thewash water supply control valve 52 to attain alternating operation ofthe upper and lower wash sprays I0, I2, and operation of the four-wayvalve 64 effects the reciprocation of the piston. The automatic controland timing of these mechanisms, according to the present disclosure,enables the automatic performance of a predetermined wash cycle inresponse to mere depression of a button. However,

a predetermined cycle of alterations of the'upper and lower wash spraysmay be initiated and maintained in any desired manner and by any means,and it should be understood that the electric control as illustrated ismerely exemplary.

As herein shown, a cam shaft 18 may be mounted at any convenientlocation, such as on the top wall 28 of the main housing. The cam shaftis driven through gears 88 by a small electric motor 82 which may be a 2R. P. M. motor, for example, so that the cam shaft, through gears 88,makes one complete revolution in seventysix seconds, for example.However, for a purpose which later will appear, the disclosed embodiment of the invention includes a clutch |9 for the cam shaft, andthe clutch is disengaged excepting when the motor 82 is energized.Hence, when the motor 82 is de-energized, the cam shaft 18 isdisconnected from its motor drive and is free to be rotatedindependently of the motor and the gears 88. Clutch 79 may be operatedby a solenoid 8| whose coil is connected (Fig. 5) to the circuit ofmotor 82 so as to be energized whenever the motor is energized. Solenoid8| has its armature 83 spring actuated in one direction and connected tothe pivoted clutch-actuating lever 85. When the solenoid 8| isenergized, its armature is actuated in opposition to its spring toengage the clutch, and the clutch continues engaged so long as motor 82is in operation. Hence, the cam shaft 'I8 is rotated whenever motor 82operates but is disconnected from the motor as soon as the motor stops.This latter is important in that it is desirable to re-set the cam shaftto a predetermined starting position following each complete or partialrotation thereof. For this purpose, a spring 81 has one end anchored andits other end connected to the cam shaft 'I8 or to some element rigidwith the cam shaft, so that, as the cam shaft is rotated in onedirection by the motor 82, energy is stored in the spring which restoresthe cam shaft to its starting position, determined by stop pin 89, assoon as the clutch 79 is disengaged when motor 82 stop-s.

The cam shaft 18 has a cam 84 fixed thereon with a high part which mayhave approximately 272 degrees of extent around the periphery of thecam, for maintaining a switch arm 86 closed during slightly more thanthree quartersy of a revolution of the cam, representing a time periodof sixty seconds, for example. The switch arm 86, when closed, completesan electric circuit Athrough the pump motor 24 and maintains the pump 28in operation until the switch arm 86 drops to the low part of cam 84 atthe end of sixty seconds, which is the predetermined duration of thewash cycle in the illustrated embodiment.

Another cam 88, fixed on cam shaft 18, controls a switch arm 98 which isheld closed throughout almost a complete revolution of the cam, therebeing only a short low part on the cam to which the switch arm 98 dropsat the end of each complete revolution. Switch arm 98, when closed,completes a holding circuit through the cam shaft motor 82 so that thismotor, having been started by depression of push button switch 92,continues in operation throughout the predetermined seventy-six secondcomplete cycle of the apparatus as herein disclosed. As soon as motor 82is started, cam 88 closes switch arm 98 to complete the holdingcircuitthrough motor 82. Also, the cam 84 immediately closes switch arm 88 tostart the pump motor 24 to keep the 6 pump motor operating for sixtyseconds or for slightly more than three quarters of a revolution of camshaft 18.

A third cam 94, iixed on cam shaft 18, operates a switch arm 96 whichcontrols the solenoid 98 which shifts the four-way valve 64 forattaining alternating operation of theupper and lower wash sprays. Asshown diagrammatically in Fig. 5, valve 64 may have an operating armv|88 connected to the armature |02 of the solenoid 98. with a spring|84A urging the armature to its outermost position as seen -in Fig. 5wherein the valve 64 is set in its position connecting the supply pipe58 throughpipe 62 to the pipe 66, and connecting pipe 68 yto pipe 18.When solenoid 98 is energized, it draws armature |82 to the right inFig. 5, thereby to effect a. clockwise rotation of valve 64 to connectthe branch supply pipe 62 to pipe 68 leading to the under side ofcylinder 56 and to connect pipe 66 from the top side of the cylinder toconnecting pipe 18, for exhaust. When solenoid 98 is de-energized itsarmature |82 returns to its position of Fig, 5, to effect acounter-clockwise rotation of valve 64 back to its position yof Fig. 5.

Cam 94, as shown, has five high portions equally distributed aroundYapproximately 272 degrees of the cam, and the switch arm 96 alternatelyengages the high and the low portions of the cam.

In the embodiment herein represented, the cam 84 energizes solenoid 98for iive six-second periods at six second intervals during the iirstsixty seconds of cam rotation, so that the upper and lower wash sprayswill be alternately on and off live times during the wash cycle and eachon period will be of six seconds duration and each oi period exceptingthe final off of the cycle ywill be of six second-s duration.

After the pump 28 has stopped, at the end of the sixty second washcycle, the washed dishes are rinsed with clean hot water before beingremoved from the apparatus. For this purpose we provide a suitablenumber of upper rinse spray nozzles |86 and a similar number of lowerrinse spray nozzles |88 within the chamber 21. As herein shown, all ofthe rinse spray nozzles are connected together for simultaneousoperation, they being supplied with clean hot water under pressurethrough branch pipe ||8 which is connected to the hot water supply pipe58 on the pressure side of manual valve 68. However, fiow to the rinsespray nozzles normally is prevented by the solenoid valve ||2 in thebranch pipe ||8 whose solenoid I4 is energized to open valve I 2 onlyduring the final eight seconds or so of each complete cycle of theapparatus. To this end, thecam shaft 18 has a fourth cam ||6 fixedthereon for controlling a switch arm ||8 which opens and closes acircuit through the solenoid I4. Cam I I6 has a single high portiondesigned to hold switch arm I8 closed only during the final eight secondperiod of a complete revolution of cam shaft 18. Hence, during the sixtysecond wash cycle, solenoid ||4 will be de-energized and valve I2 willbe closed. In the embodiment represented, the rinse valve ||2 continuesclosed for eight seconds after the wash cycle is complete and is openonly during the last eight seconds of a complete seventy-six secondcycle of the apparatus. This eight second delay between the stopping ofthe wash sprays and starting of the rinse sprays allows time for theusual dripping from the wash sprays to stop, thus avoiding dripping ofwashfwateron the dishes after they have been rinsed, whichwouldfobjectionably spot the dishes. At the end of the rinse cycle theswitch arm ||8 drops tothe low part of cam ||6 to deenergize solenoid||4, and switch arm 90 drops to the low portion of cam 88 to stop thecam shaft motor 82, and the apparatus stops in readiness forcommencement of a new cycle after the washed dishes have been removedand another rack of dishes to be washed has been inserted in chamber 21.The new cycle may .be initiated as before by merely depressing buttonswitch 92.

It is usual to maintain the wash Water in dishwashing machines at atemperature around 140 F., and to have the temperature of the rinsewater in the neighborhood of 190 F. Notwithstanding that thesetemperatures are somewhat below the boiling temperature of the water,there nevertheless is a considerable amount of vaporization of the hotwater and, in the absence of preventive measures, the hot vapor ccnnedwithin the machine has constantly increasing pressure which, whenreleased by opening the wash chamber closure 32, would rush out much inthe manner of a gust of steam. According to the invention themoisture-laden air is exhausted from chamber 2`| before the closure 32is opened. A fan is provided in a flue conduit |22 which latter opensinto the chamber 21. As herein shown, the fan |20 is connected foroperation whenever a main switch |24 is closed, excepting during thewash cycle.

It is important to note, however, that provision is made for inflow ofrelatively dry and cool air to take the place of the hot moisture-ladenair being exhausted through flue conduit |22. As best seen in Fig. 6,there is an opening |26 past the lower margin of closure 32, andexterior air streams into chamber 21 whenever fan |20 is operating, andthe incoming relatively dry and cool air flows between and around thedishes in the chamber. 21 of objectionable moisture-laden hot air priorto opening of closure 32, but induces inflow of air which dries orpartially dries the dishes prior to opening of the closure 32.

In Fig. 5, there is represented one effective embodiment of electricalcontrol means whereby operation of the fan is controlled and whereby thedescribed wash cycle of alternate operations of the upper and lower washsprays may be followed by operation of the rinse sprays. As shown, thecam-controlled operation of the switch arm 86, for controlling the pumpmotor 24, acts through a relay |28 which initially is energized by amomentary manual depression of button switch 92. Relay |28 has the threemovable contacts |29, |30, |3|', of which the contact |30 closes acircuit through the pump motor 24, and contact |3| closes a circuitthrough the cam-shaft motor 82 and clutch relay 8| in response toenergization of relay |28. Relay contact |29 also closes in response toenergization of relay |28 and completes a holding circuit through relay|28 after switch arm 86 has been closed by cam 84. The initial closingof a circuit through cam-shaft motor 82 and clutch relay 8| startsrotation of cam shaft T8 whose cam 84 immediately closes switch arm 86to complete the holding circuit through relay |28 and this circuitcontinues closed throughout the wash cycle and then opens to de-energizerelay |28 when switch arm 86 drops to the low part of cam 84, withconsequent opening of the circuit through pump motor 24.

The initial rotation of cam shaft 18 also effects closing of switch arm90 by the holding cam 88, thereby to complete a holding crcuit throughHence fan |20 not only rids chamber cam-shaft motor 82 and clutch relay8| independently of relay |28, and this latter holding circuit ismaintained closed through a complete wash and rinse cycle of the machineor throughout substantially a complete rotation of holding cam 88.

Contact |3| of relay |23 upon de-energization of the relay, closes acircuit through the motor of fan |20 so that the fan will be operatingat all times, when main switch |24 is closed, excepting during the washcycle.

The cam 04 which, as previously explained, effects five six-secondenergizations of relay- 98 at six-second intervals, to provide thealternating operation of the upper and lower wash sprays, is eiectiveonly so long as the relay |28 continues energized. The rinse cam I6, onthe other hand, can close a circuit through the solenoid ||4 of therinse valve ||2 independently of the relay |28, and does so close acircuit during the nal eight seconds of each complete wash and rinsecycle of the machine, at which time the relay |28 is deenergized.

It frequently is desirable to operate the rinse sprays independently ofany wash cycle. For example, glassware may be washed by other means thanthe present apparatus, and it may be desired to only rinse the glasswarein the present apparatus. According to the invention such an independentrinsing may be effected by merely closing a rinse button switch |32,assuming that main `switch |24 is closed. A fifth cam |34 on cam shaft'I8 actuates switch arm |36 which controls a holding circuit through arinse control relay |38 and energization of cam shaft motor 82.

Closing of switch |32 energizes relay |38 which causes closing of themovable contacts |40, |42 and |44 of the relay. Closing of relay contact|40 completes a circuit through cam shaft motor 82 and clutch relay 8|which promptly rotates cam shaft 18. Closing of relay contact |42conditions a holding circuit for relay |38 so that the holding circuitis completed through the relay as soon as cam |34 rotates to close itsswitch arm |36, and the relay continues energized until the switch arm|36 drops to the low portion of cam |34. Closing of relay contact |44energizes the rinse valve control relay ||4 to start the rinse sprays|06, |08 which continue on so long as the control relay |38 isenergized. The single high portion of cam |34 may be adapted to hold camswitch arm |36 closed for an eight second rinsing period, at the end ofwhich switch arm |36 will drop to the low portion of cam |34 tode-energize relay |38, and opening of relay contacts |40, |44de-energizes motor 82 and rinse solenoid ||4. The cam |34 may be similarto cam ||6 but has its high portion at the start of a rotation while thehigh portion of cam I6 is at the end of a rotation. Excepting whencontrol relay |38 is energized, the closing of switch arm |36 by cam |34has no effect, as during the operation of the apparatus for a washingfollowed by a rinsing.

After a separate rinsing operation, the spring 81 acts to re-set the camshaft 'I8 as soon as clutch 'I9 disengages following de-energizing ofmotor 82 and solenoid 8|. Also, a push-button stop switch |45 isprovided by which the operation of the apparatus may be stopped at anystage of a wash or rinse cycle, in which case the said spring 81 resetsthe cam shaft.

The cam shaft 18, its motor 82, all of the cam switch arms and therelays 8|, |26, |38 may be mounted as a unit in a suitable casing |46 asindicated in Fig. 1, with the push buttons 92, |34

9 and |45, and main switch |24, accessible at the front of theyapparatus.

It will be apparent from the foregoing that the invention provides anextremely efficient dishwashing apparatus which, as shown, goes througha complete cycle in response to mere depression of button 92, includinga sixty second wash cycle and an eight second rinse cycle. During thewash cycle, the dishes arevsubjected to the forceful action of the washsprays alternately, from above and from below the dishes in chamber 21,with the upper sprays operatingv at full pressure for six second periodsat six second intervals, and with the lower sprays similarly operatingduring the intervals when the upper sprays are 01T. This full pressurealternating operation of the wash sprays attains a definitely greaterwashing eiiiciency as compared with the prior practice of splitting theavailable pressure between simultaneously operating upper and lower washsprays.l Also the invention avoids any neutralizing of the agitatingeieot ofthe sprays, with each series of sprays acting entirelyseparately and uninuenced by the opposed series of sprays. What foodparticles may notbe entirely dislodged by the sprays operating with fullforce in one direction will be removed by the following sprays operatingwith full force in the opposite direction.

After the wash sprays have accomplished their work during sixty secondsof a complete cycle of the apparatus, the rinse sprays, above and belowthe dishes, operate simultaneously for eight seconds to thoroughly rinsethe dishes prior to their removal at the end of the complete cycle.

VWhenever desired, rinsing may be effected independently of a wash cycleby merely closing the rinse button switch |32 to initiate a rinse cycleof eight seconds duration, for example.

Any suitable strainer |48 may be provided in the return chamber 38within which may be suspended a suitable bag |50 of fabric or the like,for collecting food particles and other foreign matter from the waterreturning to the return chamber 38. A removable drain board |52 directsthe returning water into the bag |50 which latter is of a sort to bethrown away when it has collected such a quantity of foreign matter thatwater cannot pass freely through the bag and strainer for re-circulationby pump 20. This ensures against food particles and thelike being in there-circulated wash water.

While we have disclosed an embodiment of the invention wherein thecontrol is entirely electric, it should be understood that othermearismay be employed to initiate a wash cycle of alternately operating washsprays operating. alternately from above and below the dishes to bewashed. Also, any suitable means, manual or automatic, may be employedfor initiating a predetermined pe-l riodof operation of rinse spraysafter a .wash cycle has been completed, or independently of a washcycle.

We claim as our invention:

1. In a dish-washing apparatus, upper and lower wash water sprayconduits substantially oppositely disposed in spaced horizontal planes,the upper spray conduits having spray outlets opening toward the lowerspray conduits. and the lower spray conduits having spray outletsopening toward the upper spray conduits, whereby both the upper andlower sprays are directed acrossl substantially the same region but ingenerally opposite directions, a pump having conduit Iconnection to thesaid vspray conduits for a 10 delivering wash water to said sprayconduits, flow control means in said connection movable to one positionin which the pump output is directed only to the upper spray conduitsand movable to another position in which the pump output is directedonly to the lower spray conduits, means for driving said pump, andmechanism responsive to operation of said pump driving means for quicklyshifting said flow control means intermittently between its two saidpositions, thereby to maintain substantially continuous sprays of washwater at full pump pressure across said region but with the said spraysdirected across said region alternately in generally oppositedirections. i

2. In a dish-washing apparatus, upper and lower wash water sprayconduits substantially oppositely disposed in spaced horizontal planes,

the upper spray conduits having spray outlets opening toward the lowerspray-conduits and the lower spray conduits having spray outlets openingtoward the upper spray conduits whereby both the upper and lower spraysare directed across substantially the same region but in gen-- upperspray conduits and movable to anotherA position in which the pump outputis directed only to the lower spray conduits, means for driving saidpump, mechanism responsive to starting of said pump driving means formaintaining the pump in operation for a predetermined wash period andfor automatically` stopping it at the end of the wash period, saidmechanism including means connected to said flow control means andoperative to quickly shift said means from one of its said positions tothe other alternately at predetermined intervals during the saidwashlperiod of operation of the pump thereby to provide substantiallycontinuous wash water sprays downwardly and upwardly in said regionalternately from said upper and lower spray conduits. throughout saidpredetermined wash period of operation of the pump.

spray means in opposed relationship, and upper and lower rinse waterspray means, said wash water spray means and said rinse water sprayAmeans being located and adapted to direct their sprays in substantiallythe same region, means for supplying wash water under pressure to saidwashY water spray means, means for supplying rinse water under pressureto said rinse water spray means, flow-control means for the wash watersupply operative in one position to direct the wash water at fullpressure only to the upper,

wash water spray means, and operative in another position to direct thewash water at full pressure only to the lower wash water spray means,means for quickly shifting the said positions of the now-control means apredetermined number of times at predetermined time intervals during apredetermined wash period of Operation of the apparatus thereby toprovide substantially continuous spraying, throughout the wash periodbut with theupper V4and lower spray means operating alternately, andmeans for opening the rinse water supply means automatically after apredetermined interval following the wash period thereby to start therinse water sprays only after the said interval within which dripping 11from the upper wash water spray means will, have stopped.

4. In a dish-washing apparatus.v upper and lower wash water sprayconduits arranged in generallyl horizontally opposed relationship,v andupper and lower rinse water spray conduits arranged and adapted tovdischarge their sprays generally in the same region in which the washsprays discharge, a pump connected to the washY water spray conduits forsupplying wash water thereto at a predetermined pressure, a: rinse watersupply conduit connected to the rinse water spray' conduits forsupplying rinse water thereto at a predetermined pressure, a. valvecontrolling the water supply to thev rinse.A water spray conduits, awash water control valve between the said pump and the upper and lowerwash water sprayV conduits and operative. inonev position to direct thefull pump outputtothe upper wash water spray conduits and operative. inanother position to direct the full pumpoutput to the lower wash waterspray conduits, meansforstarting and stopping thevpump, and meansresponsive to the rinse water supply pressure for automatically quicklyshifting said` wash water control valvev alternately and at` intervals,from.v one of its said positions to the other whenever said pump isoperating.

5. In a dish-washing apparatus having upperand lower washwater sprayconduits in generally horizontal opposed relation and adapted toAdirect. sprays of wash Water generally in the same area but in oppositedirections, upper and lower rinse water spray conduits arranged andadapted to direct sprays of rinse water in oppositel directionsgenerally in the same area in whichl the wash sprays are directed, thecombination therewith. of means for supplyingr wash water to thevupperwash water sprays a, predetermined number of. times at predeterminedintervals and for. supplying wash water to the lower. washwater-sprayssubstantially throughout the said intervals when the upper wash waterspray conduits are not. bel ing supplied, and means operative only afterthe wash sprays have stopped for supplying rinsev water to the upper andlower rinse water sprayv conduits simultaneously thereby to provideoppositely directed simultaneous upper and lower rinse sprays in thesame region previously trav.-`

ersed by the alternating upper and lower wash sprays.

6.` In` a dish-washing apparatus, upper and lower wash` water spraypipes in generally horizontal opposed relation and adapted to directvsprays of wash water generally'in the same. area: but in oppositedirections, and upper and` lower rinse water spray nozzles arranged andadapted to direct sprays of rinse water in opposite directions generallyin the same` `area in which the wash sprays are directed, a pump fordelivering wash water toy said wash water spray pipes, a wash watercontrol valve operative inone position to direct the full pump outputonly to the upper wash water spray pipes and operative in anotherposition to direct the full pump4 output only to the lower wash waterspray pipes, means for drivingthe pump for a predetermined wash periodand for stopping it at the` end of the period, means operative onlyduring; said wash period for quickly shifting said wash waterv controlvalve between its said positions a prede,-l

l2 termined number of times at predetermined intervals during said washperiod thereby to provide substantially continuous wash spraysthroughoutthe wash period with the upper and lower sprays discharging'alternately, and means for supplying rinse water to both the upper andlower rinse water spray nozzles simultaneously and automatically only atthe end of a predetermined drip/periodv following said wash period.

7. In a dish-washing apparatus having upper and. lower washwater spraypipes in generally horizontal opposedlrelation and adapted to directspraysv of Wash water generally in the same area butin oppositedirections, and upper and lower rinse'ewater spray nozzles arranged andadapted to direct sprays of rinsewater in opposite directions generallyin. the same area in which the wash.spraysv arev directed, a chamberbelow said spray: pipes and nozzles for holding a 'supply of wash water,a hot water pressure supply conduit for supplying hot rinse water tosaid upper and lower. spray' nozzles and for replenishing the supply oiwash water in said chamber, manual means inv saidy conduit forcontrolling the replenishingrofsaidl chamber, electrically operatedmeans for controlling the supply of rinse water to saidspray nozzles, apump for delivering wash water from said chamber to said wash waterspray pipes, electrically operated means for driving the pump, includingmeansv for stopping it at. the end. of a predetermined period ofoperation, a valve operative in one position to direct all. of-l the;pumpA output only tol the upper wash water spray pipes and operative inanother position to direct all of the pump output to only the lower washwater spray pipes, means including a cylinder and pressure-actuatedpiston for alternating the positionsv of' said valve a predeterminednumber, of times automatically at predetermined intervals during saidperiod of operation of thepump, and means operative following stoppingot thepum-pfor opening said rinse water control means fora predeterminedperiod following stopping ofthe pump.

JOHN J. MCDONALD. STEPHEN D. KLYCE.

REFERENCES CITED The following references are of record in the le otthis patent:

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